We want to delete all files that start with a timestamp (seconds since the epoch), except the newest file (15339091628_do_not_delete) and the files root and root.sql. The easiest way to do this, is enabling the shell option extglob (“extended globbing”), which allows us to use patterns to include or exclude files of operations:

$ shopt -s extglob
$ rm !(*do_not_delete|root*)

The last command will tell Bash to remove all files, except the ones that match either one of the patterns (everything ending with do_not_delete and everything starting with root). We delimite the patterns by using a pipe character |.

Other patterns that are supported by extglob include:

?(pattern-list)
Matches zero or one occurrence of the given patterns
\*(pattern-list)
Matches zero or more occurrences of the given patterns
+(pattern-list)
Matches one or more occurrences of the given patterns
@(pattern-list)
Matches one of the given patterns
!(pattern-list)
Matches anything except one of the given patterns

To disable the extended globbing again:

$shopt -u extglob

References

To read about all the options that extglob gives you, refer to man bash (search for Pathname Expansion). Searching for shopt in the same manual page will turn up all shell options. To see which shell options are currently enables for your shell, type shopt -p at the prompt.